Curiously enough, Assassins learned hardly any unarmed combat. They were generally good enough at armed combat not to need it. Gentlemen bore arms; only the lower classes used their hands.

'I've got you,' Vimes panted. 'You're under arrest. Be under arrest, will you?'

But Cruces wouldn't let go. Vimes didn't dare let go; the gonne would be twisted out of his grip. It was pulled backwards and forwards between them in desperate, grunting concentration.

The gonne exploded.

There was a tongue of red fire, a firework stink and a zing-zing noise from three walls. Something struck Vimes' helmet and zinged away towards the ceiling.

Vimes stared at Cruces'contorted features. Then he lowered his head and yanked the gonne hard.

The Assassin screamed and let go, clutching at his nose. Vimes rolled back, gonne in both hands.

It moved. Suddenly the stock was against his shoulder and his finger was on the trigger.

You're mine.

We don't need him any more.

The shock of the voice was so great that he cried out.

He swore afterwards that he didn't pull the trigger. It moved of its own accord, pulling his finger with it. The gonne slammed into his shoulder and a six-inch hole appeared in the wall by the Assassin's head, spraying him with plaster.

Vimes was vaguely aware, through the red mist rising around his vision, of Cruces staggering to a door and lurching through it, slamming it behind him.

All that you hate, all that is wrong – I can put it right.

Vimes reached the door, and tried the handle. It was locked.

He brought the gonne around, not aware of thinking, and let the trigger pull his finger again. A large area of the door and frame became a splinter-bordered hole.

Vimes kicked the rest of it away and followed the gonne.

He was in a passageway. A dozen young men were looking at him in astonishment from half-open doors. They were all wearing black.

He was inside the Assassins' Guild.

A trainee Assassin looked at Vimes with his nostrils.

'Who are you, pray?'

The gonne swung towards him. Vimes managed to haul the barrel upwards just as it fired, and the shot took away a lot Of ceiling.

'The law, you sons of bitchesl' he shouted.

They stared at him.

Shoot them all. Clean up the world.

'Shut up!' Vimes, a red-eyed, dust-coated, slime-dripping thing from out of the earth, glared at the quaking student.

'Where did Cruces go?' The mist rolled around his head. His hand creaked with the effort of not firing.

The young man jerked a finger urgently towards a flight of stairs. He'd been standing very close when the gonne fired. Plaster dust draped him like devil's dandruff.

The gonne sped away again, dragging Vimes past the boys and up the stairs, where black mud still trailed. There was another corridor there. Doors were opening. Doors closed again after the gonne fired again, smashing a chandelier.

The corridor gave out on to a wide landing at the top of a much more impressive flight of stairs and, opposite, a big oaken door.

Vimes shot the lock off, kicked at the door and then fought the gonne long enough to duck. A crossbow bolt whirred over his head and hit someone, far down the corridor.

Shoot him! SHOOT HIM!

Cruces was standing by his desk, feverishly trying to slot another bolt into his bow—

Vimes tried to silence the singing in his ears.

But . . . why not? Why not fire? Who was this man? He'd always wanted to make the city a cleaner place, and he might as well start here. And then people would find out what the law was . . .

Clean up the world.

Noon started.

The cracked bronze bell in the Teachers' Guild began the chime, and had midday all to itself for at least seven clangs before the Guild of Bakers' clock, running fast, caught up with it.

Cruces straightened up, and began to edge towards the cover of one of the stone pillars.

'You can't shoot me,' he said, watching the gonne. 'I know the law. And so do you. You're a guard. You can't shoot me in cold blood.'

Vimes squinted along the barrel.

It'd be so easy. The trigger tugged at his finger.

A third bell began chiming.

'You can't just kill me. That's the law. And you're a guard,' Dr Cruces repeated. He licked his dry lips.

The barrel lowered a little. Cruces almost relaxed.

'Yes. I am a guard.'

The barrel rose again, pointed at Cruces' forehead.

'But when the bells stop,' said Vimes, quietly, 'I won't be a guard any more.'

Shoot him! SHOOT HIM!

Vimes forced the butt under his arm, so that he had one hand free.

'We'll do it by the rules,' he said. 'By the rules. Got to do it by the rules.'

Without looking down, he tugged his badge off the remains of his jacket. Even through the mud, it still had a gleam. He'd always kept it polished. When he spun it once or twice, like a coin, the copper caught the light.

Cruces watched it like a cat.

The bells were slackening. Most of the towers had stopped. Now there was only the sound of the gong on the Temple of Small Gods, and the bells of the Assassins' Guild, which were always fashionably late.

The gong stopped.

Dr Cruces put the crossbow, neatly and meticulously, on the desk beside him.

'There! I've put it down!'

'Ah,' said Vimes. 'But I want to make sure you don't pick it up again.'

The black bell of the Assassins' Guild hammered its way to noon.

And stopped.

Silence slammed in like a thunderclap.

The little metallic sound as Vimes' badge bounced on the floor filled it from edge to edge.

He raised the gonne and, gently, let the tension ease out of his hand.

A bell started.

It was a tinny, jolly little tune, barely to be heard at all except in this pool of silence . . .

Cling, bing, a-bing, bong . . .

. . . but much more accurate than hourglasses, water-clocks and pendulums.

'Put down the gonne, captain,' said Carrot, climbing slowly up the stairs.

He held his sword in one hand, and the presentation watch in the other.

The pounding spirit of the gonne flowing up Vimes' arms met the armies of sheer stone-headed Vimesness surging the other way.

'I should put it down, captain. You don't need it,' said Carrot, like someone speaking to a child.

Vimes stared at the thing in his hands. The screaming was muted now.

'Put that down now, Watchman! That's an order!'

The gonne hit the floor. Vimes saluted, and then realized what he was doing. He blinked at Carrot.

'Personal isn't the same as important?' he said.

'Listen,' Cruces said, 'I'm sorry about the . . . the girl, that was an accident, but I only wanted— There's evidence! There's a—'

Cruces was hardly paying any attention to the Watchmen. He pulled a leather satchel off the table and waved it at them.

'It's here! All of it, sire! Evidence! Edward was stupid, he thought it was all crowns and ceremony, he had no idea what he'd found! And then, last night, it was as if—'

'I'm not interested,' mumbled Vimes.

'The city needs a king!'

'It does not need murderers,' said Carrot.

'But—'

And then Cruces dived for the gonne and scooped it up.

One moment Vimes was trying to reassemble his thoughts, and the next they were fleeing to far corners of his consciousness. He was looking into the mouth of the gonne. It grinned at him.

Cruces slumped against the pillar, but the gonne remained steady, pointing itself at Vimes.

'It's all there, sire,' he said. 'Everything written down. The whole thing. Birthmarks and prophecies and genealogy and everything. Even your sword. It's the sword!'

'Really?' said Carrot. 'May I see?'

Carrot lowered his sword and, to Vimes' horror, walked over to the desk and pulled the bundle of documents out of the case. Cruces nodded approvingly, as if rewarding a good boy.

Carrot read a page, and turned to the next one.

'This is interesting,' he said.

'Exactly. But now we must remove this annoying policeman,' said Cruces.

Vimes felt that he could see all the way along the tube, to the little slug of metal that was soon to launch itself at him . . .

'It's a shame,' said Cruces, 'if only you had—'

Carrot stepped in front of the gonne. His arm moved in a blur. There was hardly a sound.

Pray you never face a good man, Vimes thought. He'll kill you with hardly a word.

Cruces looked down. There was blood on his shirt. He raised a hand to the sword hilt protruding from his chest, and looked back up into Carrot's eyes.

'But why? You could have been—'

And he died. The gonne fell from his hands, and fired at the floor.

There was silence.

Carrot grasped the hilt of his sword and pulled it back. The body slumped.

Vimes leaned on the table and fought to get his breath back.

'Damn . . . his . . . hide,' he panted.

'Sir?'

'He . . . he called you sire,' he said. 'What was in that—'

'You're late, captain,' said Carrot.

'Late? Late? What do you mean?' Vimes fought to prevent his brain parting company with reality.

'You were supposed to have been married—' Carrot looked at the watch, then snapped it shut and handed it to Vimes. '—two minutes ago.'

'Yes, yes. But he called you sire, I heard him—'

'Just a trick of the echo, I expect, Mr Vimes.'

A thought broke through to Vimes' attention. Carrot's sword was a couple of feet long. He'd run Cruces clean through. But Cruces had been standing with his back to—

Vimes looked at the pillar. It was granite, and a foot thick. There was no cracking. There was just a blade-shaped hole, front to back.

'Carrot—' he began.

'And you look a mess, sir. Got to get you cleaned up.'

Carrot pulled the leather satchel towards him and slung it over his shoulder.

'Carrot—'

'Sir?'

'I order you to give—'

'No, sir. You can't order me. Because you are now, sir, no offence meant, a civilian. It's a new life.'

'A civilian?'

Vimes rubbed his forehead. It was all colliding in his brain now – the gonne, the sewers, Carrot and the fact that he'd been operating on pure adrenalin, which soon presents its bill and does not give credit. He sagged.

'But this is my life. Carrot! This is my job.'

'A hot bath and a drink, sir. That's what you need,' said Carrot. 'Do you a world of good. Let's go.'

Vimes' gaze took in the fallen body of Cruces and, then, the gonne. He went to pick it up, and stopped himself in time.

Not even the wizards had something like this. One burst from a staff and they had to go and lie down.

No wonder no-one had destroyed it. You couldn't destroy something as perfect as this. It called out to something deep in the soul. Hold it in your hand, and you had power. More power than any bow or spear – they just stored up your own muscles' power, when you thought about it. But the gonne gave you power from outside. You didn't use it, it used you. Cruces had probably been a good man. He'd probably listened kindly enough to Edward, and then he'd taken the gonne, and he'd belonged to it as well.